Currently I have a Liquid Force Substance. I really like the board, but this summer I had some knee trouble. I have been thinking about getting a marius. How does the marius compare to the substance? Pop,landings,speed,tracking,etc.

the substance has a big and bucking type of pop, tracks well (too well, it's a bit grippy), lands hard and super slow.

the marius suprisingly has a bucking type of pop, too, but nowhere near as abrupt as the substance. it tracks well and can be broken free easily. it's slow when ridden flat out in the flats, but once on edge, it goes. the landings are some of the softest, if not the softest, out there.

I rode the substance for about 3 years, and have been riding a marius since about July.

they popped totally different for me. The substance would pop the same no matter how you cut. The marius liked a little more speed coming into the wake. If I would just drift in on the marius, it was like I would miss the pop.

As far as tracking, I thought they both tracked very well, and the edge hold was the same, but the marius released much quicker, which I really liked.

The landings on the Marius were somewhat softer.

And the substance only felt moderately slower.

The best advice I can give if you're having knee trouble, is to learn to land right on the transition. If you want to go out into the flats, make sure you go way out. It's when you land in the trough that you get into trouble. Speaking from experience here.